Steps taken to reduce the amount of tritium

Actions taken in response to the detection of low levels of tritium in surface and sewer water in November 2005

What did we detect in November 2005?
In November 2005, for the first time in the then-35-year history of our environmental monitoring program at Fermilab, we detected low levels of tritium in a stream leaving the Fermilab site, and in the sanitary sewers that pump water to the Batavia Wastewater Treatment Plant. The levels detected were far lower than the federal water standards that Fermilab is required to meet, and pose no threat to human health or the environment. (Our Frequently Asked Questions page provides more general information about tritium.)

How much tritium did we find?
Very little. Samples of Indian Creek, taken just inside the Fermilab boundary, found tritium concentrations of 3.3 picocuries per milliliter (pCi/ml) in Nov. 2005, and samples just below 5 pCi/ml in the sanitary sewers. In the ensuing years, these totals have risen, but remain below 10 pCi/ml in both locations.

To keep people safe, federal agencies set limits on the amount of tritium allowed in water. In 2005, the Department of Energy standard for surface water was 2,000 pCi/ml. Today, the standard is 1,900 pCi/ml. The DOE drinking water standard is 20 pCi/ml. (Indian Creek is surface water, not drinking water.) All levels of tritium measured in Indian Creek, Fermilab surface water and the sanitary sewer are well below the standards Fermilab must meet, and we are taking every possible step to keep the levels of tritium as low as reasonably achievable.

Where did the tritium come from?
Tritium is a byproduct of accelerator operations here at Fermilab. Water with low levels of tritium is pumped out of the accelerator tunnels used in our onsite industrial cooling systems and cooling ponds. The tritium found in Indian Creek stems from the more powerful proton beams needed for our latest neutrino experiments, which began in February 2005.

How did it get into the creek?
Indian Creek is a small creek that originates on the Fermilab site and leaves the lab at its southwest corner. In the fall of 2005, water escaped from cooling ponds nearby and reached the creek. We also identified other pathways that water may have taken from Fermilab ponds into Indian Creek. Low-level discharges from on-site ponds may occur in the future, in accordance with State of Illinois permits, and lead to low levels of tritium in creeks on the Fermilab site.

How did it get into the sanitary sewer?
Tritium makes its way into the sanitary sewer in a few ways. We believe the bulk of the tritium in the sewer water comes from our industrial cooling water (ICW) system. Both the ICW and the sewer system are made of pipes that are 30-40 years old, and leaks have developed over time. At some places on the Fermilab site, pipes carrying ICW and sewer water are very close together, and the ICW water seems to collect in the sewer the same way rainwater does. A very small amount of tritium also enters the sewer as a result of our regular operations.

What have we done about the tritium levels?
In response to the detection of low levels of tritium in Indian Creek and the sanitary sewer since 2005, Fermilab has taken a series of steps to reduce those levels to as low as reasonably achievable. We are committed to going beyond merely satisfying the regulatory limits, and will keep the public fully informed. Here are some of the steps we have taken:

We continue to discuss our plans and findings with the successor to the Task Force, the Fermilab Community Advisory Board, which was established in 2010.

We've changed the flow of water that could potentially contain tritium to minimize the chance of that water reaching Indian Creek. However, low-level discharges from on-site ponds into Indian Creek still happen occasionally, especially after heavy rain storms.

We identified and eliminated the largest contributor to the low levels of tritium found in the Fermilab cooling ponds. In December 2005, we began capturing water with high levels of tritium in the NuMI (neutrino beam) experimental area, and shipping that water offsite. (See this page on disposing of tritium as solid waste.)

We began evaporating a large amount of the water in the NuMI experimental area, through direct use in the Fermilab cooling system. (See this page on disposing of tritium through air emissions.)

We found that high humidity in the NuMI underground area contributed to tritium reaching the surface water. We installed dehumidification systems to significantly reduce the humidity.

In March 2008, we informed our neighbors of our plans for the NOvA experiment, which uses the same method as the MINOS experiment. NOvA requires an approximately three times more powerful particle beam in the NuMI underground hall, which will produce more tritium. In a letter to our neighbors, Director Pier Oddone shared the draft environmental assessment of the NOvA experiment. The amount of tritium in surface and sanitary sewer water on the Fermilab site will remain well below the federal water standards, and we will continue to take every possible step to keep the levels of tritium as low as reasonably achievable.

Fermilab's Tritium Working Group, comprised of scientists and engineers from across the laboratory, is reviewing the sources of tritium in surface and sanitary water, and investigating ways to minimize tritium levels.

We are incorporating the lessons we have learned into the planning and design of new particle physics experiments that require high-intensity proton beams, such as the Long-Baseline Neutrino Experiment.

We continue to periodically sample the water leaving the Fermilab site in the three creeks and the sanitary sewer. We post the results on our website here.

We continue to perform extensive monitoring throughout the site to check for any changes in the levels of tritium.

Where can you get more information?

If you have any concerns or questions about tritium at Fermilab, please call the Office of Communication at 630-840-3351. We welcome your questions and would be pleased to provide additional information.